1. Technical Field
This invention relates generally to power tools, and more particularly to a portable, multifunction, electrically powered undercut saw.
2. Description of Related Art
To install tile, wood, marble, granite, and other floor coverings, an installer often must undercut the baseboards and doors about 0.25 inch to 1.75 inches. He does so to provide sufficient space for the floor covering to fit underneath for a clean, professional installation. The tool he uses is referred to as a flush-cutting saw or undercut saw.
An existing undercut saw may take the form of the saw available under the trademark CRAIN No. 800 SUPER SAW from Crain Cutter Co., Inc. of Milpitas, Calif. It includes a flat socket set screw for mounting a 6.5-inch diameter blade on a 21/3 horsepower, 5300 rpm electric motor. With a blade guard, height adjuster, depth gauge, and associated components, the total assembly appears something like a skill saw on its side, weighs in at about 9.0 pounds, with the blade guard and depth gauge limiting blade exposure to something less than 180 degrees.
To use the existing undercut saw, the installer mounts the blade. Next, he adjusts the height adjuster for a desired height above the floor and the depth gauge to a desired depth of cut. Then, he grasps the saw with two hands, retracts the blade guard to expose the blade, and proceeds to move the undercut saw along the floor adjacent the baseboard while switching the power on and off to make the desire undercuts.
But there are some problems. The saw is relatively heavy, big, bulky, and somewhat expensive. In addition, the 6.5 inch blade tends to get very hot and warp. Furthermore, the 6.5 inch blade and bulk of the unit makes undercutting an inside ninety-degree corner somewhat awkward because the depth gauge abuts the wall either side of the corner before the corner can be undercut. The 6.5-inch diameter blade cannot reach the corner.
The depth gauge is an adjustable flat fence type of structure that extends along a chord of the blade in order to expose up to about 13/4 inches of the blade measured radially, perpendicular to the fence. In that position, the depth gauge subtends an arc of less than 180 degrees and it gets in the way. It abuts the wall before the corner is undercut. Even if the depth gauge is omitted, the size of the 6.5-inch diameter blade results in a cut greater than one-inch deep a few inches either side of the corner in order to make just a quarter inch deep cut right at the corner. Thus, floor covering installers and other users need an improved undercut saw.